A wiper is known from DE 39 34 620 A1, which is equipped with a multi-part support bracket system to lead a wiper strip. On a primary bracket with essentially U-shaped cross-section and with side walls which are arranged parallel to each other, two subordinated brackets are positioned in a swivel bearing. In the range of the swivel bearing the primary bracket overreaches one subordinated bracket, whose cross-cut is also generally U-shaped, in such a way that in the side walls of the brackets openings accommodate a joint pin and are arranged coaxially to each other. The joint pin is connected (torsion-resistant) with the subordinated bracket and its opposite ends may be rotated and are positioned in a bearing sleeve, which, in turn, is torsion-resistant and positioned in the openings in the side walls of the primary bracket. The ends of the joint pins and/or the front sides of the bearing sleeves either terminate flush at the outside of the side walls of the primary bracket or project over the outside of the side walls by a negligible amount.
From EP 06 04 322 A1 another wiper is known with a support bracket system in which the subordinated brackets are positioned similarly on the primary bracket and they may be rotated. Instead of the joint pin a type of a joint rivet is provided to form the swivel bearing. This joint rivet has a cylindrical, pin-shaped part which reaches through the aligned bore holes in the side walls of the primary bracket and the subordinated bracket, followed by a surface to mount a wind guide device. The contact surface or shoulder of the mounting surface for the wind guide device abuts on the outside of a side wall of the primary bracket, while the opposite end of the joint rivet is riveted on the outside of the opposite side wall of the primary bracket. The mounting surface of the joint rivet projects from the side of the respective side wall of the primary bracket for a length, which corresponds at least almost to the length which corresponds to the distance between the outside of the two side walls of the primary bracket. In addition, the mounting surface of the joint rivet may be profiled differently in order to obtain a firm connection with the wind guide device while the firm connection between joint rivet and wind guide device is realized either before the creation of the swivel bearing or after the creation of the swivel bearing between primary bracket and subordinated brackets.
Beside the advantage that the higher press-on force caused by the wind guide device at a higher driving speed is transferred directly to the subordinated brackets at the pressure distribution points of the primary bracket, which means, at the swivel bearings, this known solution has disadvantages. For windshield wiping equipment to function properly it is generally suggested to replace the vehicle's wipers once or twice a year, because the wiping quality diminishes with time due to the wear on the wiper. This means that with each replacement of the wiper the wind guide device is also replaced although the latter is not subjected to wear and tear and would continue to function. This results in increased costs for the wipers to be replaced and it also causes unnecessary waste. An additional aspect is that a wind guide device may be disadvantageous during operation in winter. Snow and slush may collect under the wind guide device, or between the wind guide device and the actual wiper during wiping operation, which may limit the mobility of the wiper strip or the individual brackets of the support bracket system in relation to each other. Inevitably the wiping quality would be strongly impaired which also negatively affects the driving safety. On the other hand, the driving speeds under the circumstances described above are so low already that the wind guide device is barely able to achieve a useful increase of the press-on pressure of the wiper against the windshield to be wiped. However, because the wind guide device is firmly connected with the wiper, the entire wiper would have to be replaced again by a wiper without wind guide device in the case described above. In case the wiper with wind guide device to be replaced has not yet reached is wear and tear limit and could therefore be re-used, intermediary storage would be necessary. It is obvious that this would result in additional storage expenses.
It is an object of the invention to eliminate or reduce the disadvantages described above and to further develop a wiper of the above described type in such a way that the wiper may be used either with or without wind guide device and, depending on the prevailing conditions, good wiping quality is achieved.
This invention is based on the consideration that, at low cost, a connection may be obtained between a wiper and wind guide device, which is positioned at the side of the wiper, and which may be removed if necessary, by appropriately combining elements from the two described state of the art solutions and in addition to develop them further in a special manner. In the solution according to the invention, a wiper is used again in which two subordinated brackets are connected flexibly via a joint pin or joint bolt, resp., which are positioned in respective recesses or openings, resp., in the side walls and which are axially secured. The resulting swivel joints are defined by the fact that the opposite ends of the joint pin or the free ends of the joint bolt project by a certain amount over the outside of the side walls of the primary bracket, and thereby may be used in the most simple manner as a stop bar to create the connection between the primary bracket and the wind guide device. The axial length of the stop bars, which project from the outside of the side walls, is such that they are not larger or only negligibly so than the thickness of the side walls of respective mounting brackets which are provided on the wind guide device. These two mounting brackets are located spaced apart at the side of the wind guide device at a distance which corresponds to the distance of the two swivel bearings on the primary bracket of the wiper. Each mounting bracket has essentially a U-shaped cross-section with a back and two side walls projecting from the back. The mounting brackets are adjusted to the shape of the primary bracket such that they may reach over the primary bracket from the top in the range of the swivel bearings so that the insides of the side walls abut on the outside of the side walls of the primary bracket. At least one of the two side walls of the mounting bracket may be disengaged elastically in the direction diagonally to the primary bracket. The side walls contain aligned recesses whose shape is adjusted to the above described stop bars in such a way that they may accommodate these stop bars.
In order to complete the wiper with a pertaining wind guide device the mounting brackets of the wind guide device are now slipped over the primary bracket from the top in the most simple manner in the range of the swivel bearing. At least one of the two side walls of each mounting bracket will be disengaged elastically outward no later than when the stop bars are reached so that the side walls of the mounting bracket may get over the stop bars which are located diametrically opposite. The slip-on motion of the mounting brackets takes place until the recesses in the side walls of the mounting brackets slide over the stop bars and accommodate these. In this position the insides of the side walls of the rest brackets abut on the outside of the side walls of the primary bracket and ensure a secure and sufficiently firm connection between the wiper primary bracket and the wind guide device. The stability of the mounting position of the wind guide device on the primary bracket is highest when the under side of the back of the mounting bracket also rests on the back of the primary bracket. In a preferred embodiment, on the underside of the back of the mounting bracket a raised support surface is provided with which the back of the mounting bracket rests on the back of the primary bracket, and in the remaining area between the back of the mounting bracket and the back of the primary bracket a certain gap remains. Such a design permits improved elasticity of the mounting bracket on the one hand, and on the other hand, small production tolerances may be compensated for without impairing the stability of the connection between the mounting bracket and the primary bracket. When the removal of the wind guide device from the primary bracket of the wiper is required the side walls of the mounting bracket are spread so that the stop bars are released from the recesses in the side walls of the mounting bracket. Now the wind guide device may be removed from the primary bracket from the top.
A particularly simple embodiment of the mounting brackets of the wind guide device is provided where the recesses in the side walls of the mounting bracket are designed to be aligned cylindrical openings whose diameter is adjusted to the diameter of the stop bars. This design allows a particularly firm fit of the wind guide device on the primary bracket, particularly when the front sides of the stop bars terminate flush on the outside of the side walls of the mounting bracket, or even slightly surpass those.
Another embodiment provides that the recesses in the side walls of the mounting brackets are designed to be blind holes which extend from the inside into the side walls and, depending on the stop bars, are calculated to measure so much, that the inside of the side walls of the mounting brackets may abut on the outside of the side walls of the primary bracket.
It is of particular advantage if the recesses on the outside of the side walls of the mounting bracket are closed. This improves the aesthetic impression on the one hand, and on the other hand, it prevents humidity or dirt from entering the recess from the outside and from being deposited there.
It is already known that in order to improve the bearing behavior the swivel bearings between primary bracket and subordinated brackets should be designed such that additional bearing sleeves are inserted into the aligned openings in the side walls of the primary bracket, in which the joint pin or bearing bolt, resp., is placed. When using this technique the bearing sleeves may also project for the same or a shorter length as the ends of the joint pin or the bearing bolts, resp., on the outside of the side walls of the primary bracket. For such a case a design of the recesses in the side walls of the mounting bracket such that the recesses have a larger diameter, which is adjusted to the bearing sleeve, or they have a graded one.
Of particular advantage to mount the wind guide device on the primary bracket is a design according to which insert grooves extend on the insides of the side walls of the mounting bracket, from one recess to the under edge of the side wall. The width of the insert groove is adjusted to the diameter of the recess and when additional bearing sleeves are used in the swivel bearing, it may also be designed to be graded. The stop of the mounting bracket on the primary bracket may be improved additionally by providing the insert grooves with run-up bevels which expand to the under edge of the side wall.
It is already known that when the wind guide device is arranged on the side of the support bracket system, the use of a wiper primary bracket is advantageous whose back has recesses which extend essentially across the entire width between the side walls so that the back of the primary bracket essentially is formed by individual narrow bars which connect the two side walls. When such a primary bracket is used, additional mounting hooks are provided on the wind guide device between the two mounting brackets of the wind guide device. These hooks are essentially formed by two side walls whose distance from each other is adjusted to the thickness of the respective side wall of the primary bracket and which are connected to each other by a back. When the wind guide device is mounted on the primary bracket, these additional mounting hooks are simply slipped over the side wall of the primary bracket from the top in the area of an opening in the back of the primary bracket. Additional securing of these mounting hooks on the side wall is not required. The particular job of the mounting hooks consists of additional position fixation of the wind guide device diagonal to its longitudinal expansion on the primary bracket. This compensates for possible elastic deformations of the wind guide paddle by the pressure of the air stream during operation and a stable guidance of the wind guide device on the primary bracket is achieved. These additional mounting hooks are particularly advantageous for wipers of great length and for correspondingly long wind guide devices.
For the mounting brackets and/or the mounting hooks a design is provided whereby the side walls of the mounting brackets and/or the mounting hooks extend at least to the under edge of the side walls of the primary bracket when the wind guide device is mounted on the primary bracket.
Easy mounting and a secure fit of the wind guide device on the primary bracket of the wiper is achievable by a design to which the side walls of the mounting brackets and/or the mounting hooks, before the mounting of the wind guide device on the primary bracket, run at a flat angle to each other, starting at their back.
A wiper according to the invention is particularly cost effective if the wind guide device is manufactured including the mounting bracket and/or the mounting hooks as a single piece plastic part.